Surface modified liposomes by mannosylated conjugates anchored via the adamantyl moiety in the lipid bilayer

The aim of the present study was to encapsulate mannosylated 1-aminoadamantane and mannosylated adamantyltripeptides, namely [(2R)-N-(adamant-1-yl)-3-(α,β-d-mannopyranosyloxy)-2-methylpropanamide and (2R)-N-[3-(α-d-mannopyranosyloxy)-2-methylpropanoyl]-d,l-(adamant-2-yl)glycyl-l-alanyl-d-isoglutamine] in liposomes. The characterization of liposomes, size and surface morphology was performed using dynamic light scattering (DLS) and atomic force microscopy (AFM). The results have revealed that the encapsulation of examined compounds changes the size and surface of liposomes. After the concanavalin A (ConA) was added to the liposome preparation, increase in liposome size and their aggregation has been observed. The enlargement of liposomes was ascribed to the specific binding of the ConA to the mannose present on the surface of the prepared liposomes. Thus, it has been shown that the adamantyl moiety from mannosylated 1-aminoadamantane and mannosylated adamantyltripeptides can be used as an anchor in the lipid bilayer for carbohydrate moiety exposed on the liposome surface.

Schematic presentation of ConA interaction with mannosylated adamantyltripeptides anchored via the adamantyl moiety in the lipid bilayer; it does not imply any stoichiometry of the ConA–liposome complex.Figure optionsDownload high-quality image (214 K)Download as PowerPoint slideHighlights
► Mannosylated 1-aminoadamantane and adamantylpeptides were incorporated in liposomes.
► DLS and AFM were used for liposome characterization.
► Mannosylated conjugates were anchored via adamantyl moiety in the lipid bilayer.
► The incorporated mannosylated adamantyltripeptides are grouped into domains.
► ConA confirmed exposure of the mannose on the liposome surface.